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• CodePlex Daily Summary for Monday, October 22, 2012

  CodePlex Daily Summary for Monday, October 22, 2012Popular ReleasesSQLLib: Alpha release 17: Added CLR UDFs: * clr.fn_regex_instr - similar to Oracle REGEX_INSTR * clr.fn_regex_substr - similar to Oracle REGEX_SUBSTR To deploy CLR objects copy ClrAgg.dll and ClrRegEx.dll to a folder of you choice (currently deployment script points to C:\Program Files\Microsoft SQL Server\100\CLR\ClrAgg.dll) and execute deployment scripts InstallCLRAggregates.sql and InstallCLRRegEx.sql Thank you for rating the download and/or your feedback.EPiServer CMS ElencySolutions.MultipleProperty: ElencySolutions.MultipleProperty v1.6.3: The ElencySolutions.MulitpleProperty property controls have been developed by Lee Crowe a technical developer at Fortune Cookie (London). Installation notes The property copy page can be locked down by adding the following location element, the path of this will be different depending on whether you use the embedded or non embedded resource version. When installing the nuget package these will be added automatically, examples below: Embedded: <location path="util/ElencySolutionsMultipleP...Fiskalizacija za developere: FiskalizacijaDev 1.1: Ovo je prva nadogradnja ovog projekta nakon inicijalnog predstavljanja - dodali smo nekoliko feature-a, bilo zato što smo sami primijetili da bi ih bilo dobro dodati, bilo na osnovu vaših sugestija - hvala svima koji su se ukljucili :) Ovo su stvari riješene u v1.1.: 1. Bilo bi dobro da se XML dokument koji se šalje u CIS može snimiti u datoteku (http://fiskalizacija.codeplex.com/workitem/612) 2. Podrška za COM DLL (VB6) (http://fiskalizacija.codeplex.com/workitem/613) 3. Podrška za DOS (unu...MCEBuddy 2.x: MCEBuddy 2.3.4: Changelog for 2.3.4 (32bit and 64bit) 1. Fixed a bug introduced in 2.3.3 that would cause HD recordings and recordings with multiple audio channels to fail. 2. Updated <encoder-unsupported> option to compare with all Audio tracks for videos with multiple audio tracks. 3. Fixed a bug with SRT and EDL files, when input and output directory are the same the files are not preserved.BlogEngine.NET: BlogEngine.NET 2.7 RC: Cheap ASP.NET Hosting - $4.95/Month - Click Here!! Click Here for More Info Cheap ASP.NET Hosting - $4.95/Month - Click Here! dot This is a Release Candidate version for BlogEngine.NET 2.7. The most current, stable version of BlogEngine.NET is version 2.6. Find out more about the BlogEngine.NET 2.7 RC here. To get started, be sure to check out our installation documentation. If you are upgrading from a previous version, please take a look at the Upgrading to BlogEngine.NET 2.7 instructions...Pulse: Pulse 0.6.3.0: Fixed a number of bugs that showed up since my update yesterday. Fixes included are for: - Weird issue where the initial "Nature" wallbase.cc search would duplicate itself - After changing a providers settings it wouldn't take affect until you restarted Pulse (removing or adding a provider entirely did take effect though) - Another small issue with the regex for the wallbase.cc wallpapers that I tweaked yesterday, seems good now though.Liberty: v3.4.0.0 Release 20th October 2012: Change Log -Added -Halo 4 support (invincibility, ammo editing) -Reach A warning dialog now shows up when you first attempt to swap a weapon -Fixed -A few minor bugsDoctor Reg: Doctor Reg V1.0: Doctor Reg V1.0 PT-PTkv: kv 1.0: if it were any more stable it would be a barn.LINQ for C++: cpplinq-20121020: LINQ for C++ is an attempt to bring LINQ-like list manipulation to C++11. This release includes just the source code. What's new in this release: join range operators: Inner Joins two ranges using a key selector reverse range operator distinct range operator union_with range operator intersect_with range operator except range operator concat range operator sequence_equal range aggregator to_lookup range aggregator This is a sample on how to use cpplinq: #include "cpplinq.h...helferlein_Form: 02.03.05: Requirements.Net 4.0 DotNetNuke 05.06.07 or higher, maybe it works with lower versions, but I developed it on this one and tested it on DotNetNuke 06.02.00 as well helferlein_BabelFish version 01.01.03 - please upgrade this first! Issues fixed Fixed issue with all users from all portals are listed as Host users in the sender options (E-Mail Options - Sender - ALL Users Listed) Registered postback-button for Excel-Export on Form submission edit control Changed behaviour Due to some mis...ClosedXML - The easy way to OpenXML: ClosedXML 0.68.1: ClosedXML now resolves formulas! Yes it finally happened. If you call cell.Value and it has a formula the library will try to evaluate the formula and give you the result. For example: var wb = new XLWorkbook(); var ws = wb.AddWorksheet("Sheet1"); ws.Cell("A1").SetValue(1).CellBelow().SetValue(1); ws.Cell("B1").SetValue(1).CellBelow().SetValue(1); ws.Cell("C1").FormulaA1 = "\"The total value is: \" & SUM(A1:B2)"; var...Orchard Project: Orchard 1.6 RC: RELEASE NOTES This is the Release Candidate version of Orchard 1.6. You should use this version to prepare your current developments to the upcoming final release, and report problems. Please read our release notes for Orchard 1.6 RC: http://docs.orchardproject.net/Documentation/Orchard-1-6-Release-Notes Please do not post questions as reviews. Questions should be posted in the Discussions tab, where they will usually get promptly responded to. If you post a question as a review, you wil...Rawr: Rawr 5.0.1: This is the Downloadable WPF version of Rawr!For web-based version see http://elitistjerks.com/rawr.php You can find the version notes at: http://rawr.codeplex.com/wikipage?title=VersionNotes Rawr Addon (NOT UPDATED YET FOR MOP)We now have a Rawr Official Addon for in-game exporting and importing of character data hosted on Curse. The Addon does not perform calculations like Rawr, it simply shows your exported Rawr data in wow tooltips and lets you export your character to Rawr (including ba...Yahoo! UI Library: YUI Compressor for .Net: Version 2.1.1.0 - Sartha (BugFix): - Revered back the embedding of the 2x assemblies.Visual Studio Team Foundation Server Branching and Merging Guide: v2.1 - Visual Studio 2012: Welcome to the Branching and Merging Guide What is new? The Version Control specific discussions have been moved from the Branching and Merging Guide to the new Advanced Version Control Guide. The Branching and Merging Guide and the Advanced Version Control Guide have been ported to the new document style. See http://blogs.msdn.com/b/willy-peter_schaub/archive/2012/10/17/alm-rangers-raising-the-quality-bar-for-documentation-part-2.aspx for more information. Quality-Bar Details Documentatio...D3 Loot Tracker: 1.5.5: Compatible with 1.05.Write Once, Play Everywhere: MonoGame 3.0 (BETA): This is a beta release of the up coming MonoGame 3.0. It contains an Installer which will install a binary release of MonoGame on windows boxes with the following platforms. Windows, Linux, Android and Windows 8. If you need to build for iOS or Mac you will need to get the source code at this time as the installers for those platforms are not available yet. The installer will also install a bunch of Project templates for Visual Studio 2010 , 2012 and MonoDevleop. For those of you wish...CODE Framework: 4.0.21017.0: See change log in the Documentation section for details.Magelia WebStore Open-source Ecommerce software: Magelia WebStore 2.1: Add support for .net 4.0 to Magelia.Webstore.Client and StarterSite version 2.1.254.3 Scheduler Import & Export feature (for Professional and Entreprise Editions) UTC datetime and timezone support .net 4.5 and Visual Studio 2012 migration client magelia global refactoring release of a nugget package to help developers speed up development http://nuget.org/packages/Magelia.Webstore.Client optimization of the data update mechanism (a.k.a. "burst") Performance improvment of the d...New ProjectsAdvanced Systems Generator: A very advanced systems generator in the first phase...planning. Android Phones: Creating Web 2.0 site featuring different types of Android phone where Users and fun of the phones can rate, evaluate and comment on different android phonesAppFabpraisal: AppFabPraisal is a project containing Concept Work around Health Monitoring in AppFabric.ASP.NET Web 2.0 Proje: this is a testAssignment1: This is a simple project allow users to sum two numbersBarryKileyiRobotics: The irobotics websiteBI Loteria: BI de jogos de loteria e lotofacil, para maximizar o numero de acerto em logos desse tipo.BKileyiRoboticsA1: iRobotics BlipiNET: Dostepowa biblioteka .NET do funkcjonalnosci API serwisu Blipi.plCAPRSFinal: Subversion, pruebas unitarias, etc.CityON: l' applicazione fornirà servizi informativi e supporterà l' utente nella pianificazione delle attivitàCryptographer: Cryptographer is a simple encryption/decryption application written in C# WinForms. It allows encryption and decryption using MD5, Rijndael, XOR and Hex.Design Patterns at TUM: Implement and provide the set of design patters in the area of software engineering. DigitalCV: DigitalCV is an API and editor for creating digital curriculum vitaes.Energy Informatics: The idea of this project is to follow a research in the area of energy informatics where we can provide value from the computer science.Ficharts.Net: ??Ficharts?Asp.Net????FlakerNET: Dostepowa biblioteka .NET do funkcjonalnosci API serwisu Flaker.plgillsassignment2: This is my second assignment which has 2 aspx pages.Image Space Occlusion Culling Engine: ISOCE is an Image Space Occlusion Culling Engine optimized to perform occlusion culling in CPU. Developed in C++ using SIMD optimizations.Liubaobao File Manager: A web based file managernetception: netception is an error tracking system aimed at enterprise environments. it aims to build on existing logging projects with business related informationPhoneGap MVC: Demo MVC application using PhoneGapProjetoIntegrador: Projeto Integrador para PUCPR Londrina.Quicklight: The Quicklight project that allows a developer to write anything from Rich Internet Applications to Apps for mobile phones using C# and HTML based Razor viewsRarawel: Crawl website with custom URIs and grab contentSharePoint Online Helper Library: Use .NET code or PowerShell to automate SharePoint Online deployment tasks, such as authenticating without browser, and activate sandbox solutions.SharkCrawler: SharkCrawler is a simple web page crawler written in C# for demonstration of how regular crawler is working.Shin Warrior Players Union: This is a ASP.NET Web 2.0 Project for WSCC coursework.Simple Servers Monitor: Monitor Servers via simple and yet comprehensive interface. Test Hgsubversion: For Testing hgsubversion.Visualizador de escandallos: Visualizador recursivo de estructuras tipo arbol para escandallos de producción.WebscriptingAssignment: sum of two numbersWrapCode - Template: WrapCode.com Custom WordPress template.XMLCatalogueTemplate(C#): MSP????????????????????????????。 ?????????????????。

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• Ways to organize interface and implementation in C++

  - by Felix Dombek

  I've seen that there are several different paradigms in C++ concerning what goes into the header file and what to the cpp file. AFAIK, most people, especially those from a C background, do: foo.h class foo { private: int mem; int bar(); public: foo(); foo(const foo&); foo& operator=(foo); ~foo(); } foo.cpp #include foo.h foo::bar() { return mem; } foo::foo() { mem = 42; } foo::foo(const foo& f) { mem = f.mem; } foo::operator=(foo f) { mem = f.mem; } foo::~foo() {} int main(int argc, char *argv[]) { foo f; } However, my lecturers usually teach C++ to beginners like this: foo.h class foo { private: int mem; int bar() { return mem; } public: foo() { mem = 42; } foo(const foo& f) { mem = f.mem; } foo& operator=(foo f) { mem = f.mem; } ~foo() {} } foo.cpp #include foo.h int main(int argc, char* argv[]) { foo f; } // other global helper functions, DLL exports, and whatnot Originally coming from Java, I have also always stuck to this second way for several reasons, such as that I only have to change something in one place if the interface or method names change, that I like the different indentation of things in classes when I look at their implementation, and that I find names more readable as foo compared to foo::foo. I want to collect pro's and con's for either way. Maybe there are even still other ways? One disadvantage of my way is of course the need for occasional forward declarations.

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• StreamInsight 2.1, meet LINQ

  - by Roman Schindlauer

  Someone recently called LINQ “magic” in my hearing. I leapt to LINQ’s defense immediately. Turns out some people don’t realize “magic” is can be a pejorative term. I thought LINQ needed demystification. Here’s your best demystification resource: http://blogs.msdn.com/b/mattwar/archive/2008/11/18/linq-links.aspx. I won’t repeat much of what Matt Warren says in his excellent series, but will talk about some core ideas and how they affect the 2.1 release of StreamInsight. Let’s tell the story of a LINQ query. Compile time It begins with some code: IQueryable<Product> products = ...; var query = from p in products             where p.Name == "Widget"             select p.ProductID; foreach (int id in query) {     ... When the code is compiled, the C# compiler (among other things) de-sugars the query expression (see C# spec section 7.16): ... var query = products.Where(p => p.Name == "Widget").Select(p => p.ProductID); ... Overload resolution subsequently binds the Queryable.Where<Product> and Queryable.Select<Product, int> extension methods (see C# spec sections 7.5 and 7.6.5). After overload resolution, the compiler knows something interesting about the anonymous functions (lambda syntax) in the de-sugared code: they must be converted to expression trees, i.e.,“an object structure that represents the structure of the anonymous function itself” (see C# spec section 6.5). The conversion is equivalent to the following rewrite: ... var prm1 = Expression.Parameter(typeof(Product), "p"); var prm2 = Expression.Parameter(typeof(Product), "p"); var query = Queryable.Select<Product, int>(     Queryable.Where<Product>(         products,         Expression.Lambda<Func<Product, bool>>(Expression.Property(prm1, "Name"), prm1)),         Expression.Lambda<Func<Product, int>>(Expression.Property(prm2, "ProductID"), prm2)); ... If the “products” expression had type IEnumerable<Product>, the compiler would have chosen the Enumerable.Where and Enumerable.Select extension methods instead, in which case the anonymous functions would have been converted to delegates. At this point, we’ve reduced the LINQ query to familiar code that will compile in C# 2.0. (Note that I’m using C# snippets to illustrate transformations that occur in the compiler, not to suggest a viable compiler design!) Runtime When the above program is executed, the Queryable.Where method is invoked. It takes two arguments. The first is an IQueryable<> instance that exposes an Expression property and a Provider property. The second is an expression tree. The Queryable.Where method implementation looks something like this: public static IQueryable<T> Where<T>(this IQueryable<T> source, Expression<Func<T, bool>> predicate) {     return source.Provider.CreateQuery<T>(     Expression.Call(this method, source.Expression, Expression.Quote(predicate))); } Notice that the method is really just composing a new expression tree that calls itself with arguments derived from the source and predicate arguments. Also notice that the query object returned from the method is associated with the same provider as the source query. By invoking operator methods, we’re constructing an expression tree that describes a query. Interestingly, the compiler and operator methods are colluding to construct a query expression tree. The important takeaway is that expression trees are built in one of two ways: (1) by the compiler when it sees an anonymous function that needs to be converted to an expression tree, and; (2) by a query operator method that constructs a new queryable object with an expression tree rooted in a call to the operator method (self-referential). Next we hit the foreach block. At this point, the power of LINQ queries becomes apparent. The provider is able to determine how the query expression tree is evaluated! The code that began our story was intentionally vague about the definition of the “products” collection. Maybe it is a queryable in-memory collection of products: var products = new[]     { new Product { Name = "Widget", ProductID = 1 } }.AsQueryable(); The in-memory LINQ provider works by rewriting Queryable method calls to Enumerable method calls in the query expression tree. It then compiles the expression tree and evaluates it. It should be mentioned that the provider does not blindly rewrite all Queryable calls. It only rewrites a call when its arguments have been rewritten in a way that introduces a type mismatch, e.g. the first argument to Queryable.Where<Product> being rewritten as an expression of type IEnumerable<Product> from IQueryable<Product>. The type mismatch is triggered initially by a “leaf” expression like the one associated with the AsQueryable query: when the provider recognizes one of its own leaf expressions, it replaces the expression with the original IEnumerable<> constant expression. I like to think of this rewrite process as “type irritation” because the rewritten leaf expression is like a foreign body that triggers an immune response (further rewrites) in the tree. The technique ensures that only those portions of the expression tree constructed by a particular provider are rewritten by that provider: no type irritation, no rewrite. Let’s consider the behavior of an alternative LINQ provider. If “products” is a collection created by a LINQ to SQL provider: var products = new NorthwindDataContext().Products; the provider rewrites the expression tree as a SQL query that is then evaluated by your favorite RDBMS. The predicate may ultimately be evaluated using an index! In this example, the expression associated with the Products property is the “leaf” expression. StreamInsight 2.1 For the in-memory LINQ to Objects provider, a leaf is an in-memory collection. For LINQ to SQL, a leaf is a table or view. When defining a “process” in StreamInsight 2.1, what is a leaf? To StreamInsight a leaf is logic: an adapter, a sequence, or even a query targeting an entirely different LINQ provider! How do we represent the logic? Remember that a standing query may outlive the client that provisioned it. A reference to a sequence object in the client application is therefore not terribly useful. But if we instead represent the code constructing the sequence as an expression, we can host the sequence in the server: using (var server = Server.Connect(...)) {     var app = server.Applications["my application"];     var source = app.DefineObservable(() => Observable.Range(0, 10, Scheduler.NewThread));     var query = from i in source where i % 2 == 0 select i; } Example 1: defining a source and composing a query Let’s look in more detail at what’s happening in example 1. We first connect to the remote server and retrieve an existing app. Next, we define a simple Reactive sequence using the Observable.Range method. Notice that the call to the Range method is in the body of an anonymous function. This is important because it means the source sequence definition is in the form of an expression, rather than simply an opaque reference to an IObservable<int> object. The variation in Example 2 fails. Although it looks similar, the sequence is now a reference to an in-memory observable collection: var local = Observable.Range(0, 10, Scheduler.NewThread); var source = app.DefineObservable(() => local); // can’t serialize ‘local’! Example 2: error referencing unserializable local object The Define* methods support definitions of operator tree leaves that target the StreamInsight server. These methods all have the same basic structure. The definition argument is a lambda expression taking between 0 and 16 arguments and returning a source or sink. The method returns a proxy for the source or sink that can then be used for the usual style of LINQ query composition. The “define” methods exploit the compile-time C# feature that converts anonymous functions into translatable expression trees! Query composition exploits the runtime pattern that allows expression trees to be constructed by operators taking queryable and expression (Expression<>) arguments. The practical upshot: once you’ve Defined a source, you can compose LINQ queries in the familiar way using query expressions and operator combinators. Notably, queries can be composed using pull-sequences (LINQ to Objects IQueryable<> inputs), push sequences (Reactive IQbservable<> inputs), and temporal sequences (StreamInsight IQStreamable<> inputs). You can even construct processes that span these three domains using “bridge” method overloads (ToEnumerable, ToObservable and To*Streamable). Finally, the targeted rewrite via type irritation pattern is used to ensure that StreamInsight computations can leverage other LINQ providers as well. Consider the following example (this example depends on Interactive Extensions): var source = app.DefineEnumerable((int id) =>     EnumerableEx.Using(() =>         new NorthwindDataContext(), context =>             from p in context.Products             where p.ProductID == id             select p.ProductName)); Within the definition, StreamInsight has no reason to suspect that it ‘owns’ the Queryable.Where and Queryable.Select calls, and it can therefore defer to LINQ to SQL! Let’s use this source in the context of a StreamInsight process: var sink = app.DefineObserver(() => Observer.Create<string>(Console.WriteLine)); var query = from name in source(1).ToObservable()             where name == "Widget"             select name; using (query.Bind(sink).Run("process")) {     ... } When we run the binding, the source portion which filters on product ID and projects the product name is evaluated by SQL Server. Outside of the definition, responsibility for evaluation shifts to the StreamInsight server where we create a bridge to the Reactive Framework (using ToObservable) and evaluate an additional predicate. It’s incredibly easy to define computations that span multiple domains using these new features in StreamInsight 2.1! Regards, The StreamInsight Team

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• Working with Reporting Services Filters–Part 5: OR Logic

  - by smisner

  When you combine multiple filters, Reporting Services uses AND logic. Once upon a time, there was actually a drop-down list for selecting AND or OR between filters which was very confusing to people because often it was grayed out. Now that selection is gone, but no matter. It wouldn’t help us solve the problem that I want to describe today. As with many problems, Reporting Services gives us more than one way to apply OR logic in a filter. If I want a filter to include this value OR that value for the same field, one approach is to set up the filter is to use the IN operator as I explained in Part 1 of this series. But what if I want to base the filter on two different fields? I  need a different solution. Using the AdventureWorksDW2008R2 database, I have a report that lists product sales: Let’s say that I want to filter this report to show only products that are Bikes (a category) OR products for which sales were greater than $1,000 in a year. If I set up the filter like this: Expression Data Type Operator Value [Category] Text = Bikes [SalesAmount]   > 1000 Then AND logic is used which means that both conditions must be true. That’s not the result I want. Instead, I need to set up the filter like this: Expression Data Type Operator Value =Fields!EnglishProductCategoryName.Value = "Bikes" OR Fields!SalesAmount.Value > 1000 Boolean = =True The OR logic needs to be part of the expression so that it can return a Boolean value that we test against the Value. Notice that I have used =True rather than True for the value. The filtered report appears below. Any non-bike product appears only if the total sales exceed $1,000, whereas Bikes appear regardless of sales. (You can’t see it in this screenshot, but Mountain-400-W Silver, 38 has sales of $923 in 2007 but gets included because it is in the Bikes category.)

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• How to target just one search engine and optimise for that

  - by mickburkejnr

  I've been dabbling with SEO a lot in the last 6 months, and one thing that has surprised me is the disparity between Google and Bing in the way they deliver results. A website ranked for a specific keyword/phrase on Google may rank 3rd on the first page, but using the same keyword/phrase on Bing will display the same website but ranked 15th for the exact same keyword/phrase. I came up with the idea to increase traffic to my website by targetting Bing instead of Google for several reasons. The biggest one is that while it's not the biggest search provider, people still use it, and I feel that if other websites have been "neglected" and not optimised for Bing my website would stand a better chance of getting near the top of their search rankings. The question is though how would I do this? A lot of the SEO advice on the internet is generic, but I can't help feeling it's Google orientated for obvious reasons. How could I optimise my website to be Bing friendly, rather than Google friendly? I know it sounds like suicide as I'm taking myself out of the Google mindset, but I feel it could work wonders for traffic to the site.

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• New features in SQL Prompt 6.4

  - by Tom Crossman

  We’re pleased to announce a new beta version of SQL Prompt. We’ve been trying out a few new core technologies, and used them to add features and bug fixes suggested by users on the SQL Prompt forum and suggestions forum. You can download the SQL Prompt 6.4 beta here (zip file). Let us know what you think! New features Execute current statement In a query window, you can now execute the SQL statement under your cursor by pressing Shift + F5. For example, if you have a query containing two statements and your cursor is placed on the second statement: When you press Shift + F5, only the second statement is executed:   Insert semicolons You can now use SQL Prompt to automatically insert missing semicolons after each statement in a query. To insert semicolons, go to the SQL Prompt menu and click Insert Semicolons. Alternatively, hold Ctrl and press B then C. BEGIN…END block highlighting When you place your cursor over a BEGIN or END keyword, SQL Prompt now automatically highlights the matching keyword: Rename variables and aliases You can now use SQL Prompt to rename all occurrences of a variable or alias in a query. To rename a variable or alias, place your cursor over an instance of the variable or alias you want to rename and press F2: Improved loading dialog box The database loading dialog box now shows actual progress, and you can cancel loading databases:   Single suggestion improvement SQL Prompt no longer suggests keywords if the keyword has been typed and no other suggestions exist. Performance improvement SQL Prompt now has less impact on Management Studio start up time. What do you think? We want to hear your feedback about the beta. If you have any suggestions, or bugs to report, tell us on the SQL Prompt forum or our suggestions forum.

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• Using visitor pattern with large object hierarchy

  - by T. Fabre

  Context I've been using with a hierarchy of objects (an expression tree) a "pseudo" visitor pattern (pseudo, as in it does not use double dispatch) : public interface MyInterface { void Accept(SomeClass operationClass); } public class MyImpl : MyInterface { public void Accept(SomeClass operationClass) { operationClass.DoSomething(); operationClass.DoSomethingElse(); // ... and so on ... } } This design was, however questionnable, pretty comfortable since the number of implementations of MyInterface is significant (~50 or more) and I didn't need to add extra operations. Each implementation is unique (it's a different expression or operator), and some are composites (ie, operator nodes that will contain other operator/leaf nodes). Traversal is currently performed by calling the Accept operation on the root node of the tree, which in turns calls Accept on each of its child nodes, which in turn... and so on... But the time has come where I need to add a new operation, such as pretty printing : public class MyImpl : MyInterface { // Property does not come from MyInterface public string SomeProperty { get; set; } public void Accept(SomeClass operationClass) { operationClass.DoSomething(); operationClass.DoSomethingElse(); // ... and so on ... } public void Accept(SomePrettyPrinter printer) { printer.PrettyPrint(this.SomeProperty); } } I basically see two options : Keep the same design, adding a new method for my operation to each derived class, at the expense of maintainibility (not an option, IMHO) Use the "true" Visitor pattern, at the expense of extensibility (not an option, as I expect to have more implementations coming along the way...), with about 50+ overloads of the Visit method, each one matching a specific implementation ? Question Would you recommand using the Visitor pattern ? Is there any other pattern that could help solve this issue ?

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• Using ASP.NET MVC, Linq To SQL, and StructureMap causing DataContext to cache data

  - by Dragn1821

  I'll start by telling my project setup: ASP.NET MVC 1.0 StructureMap 2.6.1 VB I've created a bootstrapper class shown here: Imports StructureMap Imports DCS.Data Imports DCS.Services Public Class BootStrapper Public Shared Sub ConfigureStructureMap() ObjectFactory.Initialize(AddressOf StructureMapRegistry) End Sub Private Shared Sub StructureMapRegistry(ByVal x As IInitializationExpression) x.AddRegistry(New MainRegistry()) x.AddRegistry(New DataRegistry()) x.AddRegistry(New ServiceRegistry()) x.Scan(AddressOf StructureMapScanner) End Sub Private Shared Sub StructureMapScanner(ByVal scanner As StructureMap.Graph.IAssemblyScanner) scanner.Assembly("DCS") scanner.Assembly("DCS.Data") scanner.Assembly("DCS.Services") scanner.WithDefaultConventions() End Sub End Class I've created a controller factory shown here: Imports System.Web.Mvc Imports StructureMap Public Class StructureMapControllerFactory Inherits DefaultControllerFactory Protected Overrides Function GetControllerInstance(ByVal controllerType As System.Type) As System.Web.Mvc.IController Return ObjectFactory.GetInstance(controllerType) End Function End Class I've modified the Global.asax.vb as shown here: ... Sub Application_Start() RegisterRoutes(RouteTable.Routes) 'StructureMap BootStrapper.ConfigureStructureMap() ControllerBuilder.Current.SetControllerFactory(New StructureMapControllerFactory()) End Sub ... I've added a Structure Map registry file to each of my three projects: DCS, DCS.Data, and DCS.Services. Here is the DCS.Data registry: Imports StructureMap.Configuration.DSL Public Class DataRegistry Inherits Registry Public Sub New() 'Data Connections. [For](Of DCSDataContext)() _ .HybridHttpOrThreadLocalScoped _ .Use(New DCSDataContext()) 'Repositories. [For](Of IShiftRepository)() _ .Use(Of ShiftRepository)() [For](Of IMachineRepository)() _ .Use(Of MachineRepository)() [For](Of IShiftSummaryRepository)() _ .Use(Of ShiftSummaryRepository)() [For](Of IOperatorRepository)() _ .Use(Of OperatorRepository)() [For](Of IShiftSummaryJobRepository)() _ .Use(Of ShiftSummaryJobRepository)() End Sub End Class Everything works great as far as loading the dependecies, but I'm having problems with the DCSDataContext class that was genereated by Linq2SQL Classes. I have a form that posts to a details page (/Summary/Details), which loads in some data from SQL. I then have a button that opens a dialog box in JQuery, which populates the dialog from a request to (/Operator/Modify). On the dialog box, the form has a combo box and an OK button that lets the user change the operator's name. Upon clicking OK, the form is posted to (/Operator/Modify) and sent through the service and repository layers of my program and updates the record in the database. Then, the RedirectToAction is called to send the user back to the details page (/Summary/Details) where there is a call to pull the data from SQL again, updating the details view. Everything works great, except the details view does not show the new operator that was selected. I can step through the code and see the DCSDataContext class being accessed to update the operator (which does actually change the database record), but when the DCSDataContext is accessed to reload the details objects, it pulls in the old value. I'm guessing that StructureMap is causing not only the DCSDataContext class but also the data to be cached? I have also tried adding the following to the Global.asax, but it just ends up crashing the program telling me the DCSDataContext has been disposed... Private Sub MvcApplication_EndRequest(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.EndRequest StructureMap.ObjectFactory.ReleaseAndDisposeAllHttpScopedObjects() End Sub Can someone please help?

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• Problem with combination boost::exception and boost::variant

  - by Rick

  Hello all, I have strange problem with two-level variant struct when boost::exception is included. I have following code snippet: #include <boost/variant.hpp> #include <boost/exception/all.hpp> typedef boost::variant< int > StoredValue; typedef boost::variant< StoredValue > ExpressionItem; inline std::ostream& operator << ( std::ostream & os, const StoredValue& stvalue ) { return os;} inline std::ostream& operator << ( std::ostream & os, const ExpressionItem& stvalue ) { return os; } When I try to compile it, I have following error: boost/exception/detail/is_output_streamable.hpp(45): error C2593: 'operator <<' is ambiguous test.cpp(11): could be 'std::ostream &operator <<(std::ostream &,const ExpressionItem &)' [found using argument-dependent lookup] test.cpp(8): or 'std::ostream &operator <<(std::ostream &,const StoredValue &)' [found using argument-dependent lookup] 1> while trying to match the argument list '(std::basic_ostream<_Elem,_Traits>, const boost::error_info<Tag,T>)' 1> with 1> [ 1> _Elem=char, 1> _Traits=std::char_traits<char> 1> ] 1> and 1> [ 1> Tag=boost::tag_original_exception_type, 1> T=const type_info * 1> ] Code snippet is simplified as much as possible, in the real code are structures much more complicated and each variant has five sub-types. When i remove #include and try following test snippet, program is compiled correctly: void TestVariant() { ExpressionItem test; std::stringstream str; str << test; } Could someone please advise me how to define operators << in order to function even when using boost::Exception ? Thanks and regards Rick

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• Are there known problems with >= and <= and the eval function in JS?

  - by Augier

  I am currently writing a JS rules engine which at one point needs to evaluate boolean expressions using the eval() function. Firstly I construct an equation as such: var equation = "relation.relatedTrigger.previousValue" + " " + relation.operator + " " + "relation.value"; relation.relatedTrigger.previousValue is the value I want to compare. relation.operator is the operator (either "==", "!=", <=, "<", "", ="). relation.value is the value I want to compare with. I then simply pass this string to the eval function and it returns true or false as such: return eval(equation); This works absolutely fine (with words and numbers) or all of the operators except for = and <=. E.g. When evaluating the equation: relation.relatedTrigger.previousValue <= 100 It returns true when previousValue = 0,1,10,100 & all negative numbers but false for everything in between. I would greatly appreciate the help of anyone to either answer my question or to help me find an alternative solution. Regards, Augier. P.S. I don't need a speech on the insecurities of the eval() function. Any value given to relation.relatedTrigger.previousValue is predefined. edit: Here is the full function: function evaluateRelation(relation) { console.log("Evaluating relation") var currentValue; //if multiple values if(relation.value.indexOf(";") != -1) { var values = relation.value.split(";"); for (x in values) { var equation = "relation.relatedTrigger.previousValue" + " " + relation.operator + " " + "values[x]"; currentValue = eval(equation); if (currentValue) return true; } return false; } //if single value else { //Evaluate the relation and get boolean var equation = "relation.relatedTrigger.previousValue" + " " + relation.operator + " " + "relation.value"; console.log("relation.relatedTrigger.previousValue " + relation.relatedTrigger.previousValue); console.log(equation); return eval(equation); } } Answer: Provided by KennyTM below. A string comparison doesn't work. Converting to a numerical was needed.

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• Is it ok to dynamic cast "this" as a return value?

  - by Panayiotis Karabassis

  This is more of a design question. I have a template class, and I want to add extra methods to it depending on the template type. To practice the DRY principle, I have come up with this pattern (definitions intentionally omitted): template <class T> class BaseVector: public boost::array<T, 3> { protected: BaseVector<T>(const T x, const T y, const T z); public: bool operator == (const Vector<T> &other) const; Vector<T> operator + (const Vector<T> &other) const; Vector<T> operator - (const Vector<T> &other) const; Vector<T> &operator += (const Vector<T> &other) { (*this)[0] += other[0]; (*this)[1] += other[1]; (*this)[2] += other[2]; return *dynamic_cast<Vector<T> * const>(this); } } template <class T> class Vector : public BaseVector<T> { public: Vector<T>(const T x, const T y, const T z) : BaseVector<T>(x, y, z) { } }; template <> class Vector<double> : public BaseVector<double> { public: Vector<double>(const double x, const double y, const double z); Vector<double>(const Vector<int> &other); double norm() const; }; I intend BaseVector to be nothing more than an implementation detail. This works, but I am concerned about operator+=. My question is: is the dynamic cast of the this pointer a code smell? Is there a better way to achieve what I am trying to do (avoid code duplication, and unnecessary casts in the user code)? Or am I safe since, the BaseVector constructor is private?

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• How to pass operators as parameters

  - by Rodion Ingles

  I have to load an array of doubles from a file, multiply each element by a value in a table (different values for different elements), do some work on it, invert the multiplication (that is, divide) and then save the data back to file. Currently I implement the multiplication and division process in two separate methods. Now there is some extra work behind the scenes but apart from the specific statements where the multiplication/division occurs, the rest of the code is identical. As you can imagine, with this approach you have to be very careful making any changes. The surrounding code is not trivial, so its either a case of manually editing each method or copying changes from one method to the other and remembering to change the * and / operators. After too many close calls I am fed up of this and would like to make a common function which implements the common logic and two wrapper functions which pass which operator to use as a parameter. My initial approach was to use function pointers: MultiplyData(double data) { TransformData(data, &(operator *)); } DivideData(double data) { TransformData(data, &(operator /)); } TransformData(double data, double (*func)(double op1, double op2)) { /* Do stuff here... */ } However, I can't pass the operators as pointers (is this because it is an operator on a native type?), so I tried to use function objects. Initially I thought that multiplies and divides functors in <functional> would be ideal: MultiplyData(double data) { std::multiplies<double> multFunct; TransformData(data, &multFunct); } DivideData(double data) { std::divides<double> divFunct; TransformData(data, &divFunct); } TransformData(double data, std::binary_function<double, double, double> *funct) { /* Do stuff here... */ } As you can see I was trying to use a base class pointer to pass the functor polymorphically. The problem is that std::binary_function does not declare an operator() member for the child classes to implement. Is there something I am missing, or is the solution to implement my own functor heirarchy (which really seems more trouble than it is worth)?

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• Understanding C++ dynamic allocation

  - by kiokko89

  Consider the following code: class CString { private: char* buff; size_t len; public: CString(const char* p):len(0), buff(nullptr) { cout << "Constructor called!"<<endl; if (p!=nullptr) { len= strlen(p); if (len>0) { buff= new char[len+1]; strcpy_s(buff, len+1, p); } } } CString (const CString& s) { cout << "Copy constructor called!"<<endl; len= s.len; buff= new char[len+1]; strcpy_s(buff, len+1, s.buff); } CString& operator = (const CString& rhs) { cout << "Assignment operator called!"<<endl; if (this != &rhs) { len= rhs.len; delete[] buff; buff= new char[len+1]; strcpy_s(buff, len+1, rhs.buff); } return *this; } CString operator + (const CString& rhs) const { cout << "Addition operator called!"<<endl; size_t lenght= len+rhs.len+1; char* tmp = new char[lenght]; strcpy_s(tmp, lenght, buff); strcat_s(tmp, lenght, rhs.buff); return CString(tmp); } ~CString() { cout << "Destructor called!"<<endl; delete[] buff; } }; int main() { CString s1("Hello"); CString s2("World"); CString s3 = s1+s2; } My problem is that I don't know how to delete the memory allocated in the addition operator function(char* tmp = new char[length]). I couldn't do this in the constructor(I tried delete[] p) because it is also called from the main function with arrays of chars as parameters which are not allocated on the heap...How can I get around this? (Sorry for my bad English...)

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• C++ keeping a list of objects and calling a contructor through another function

  - by Nona Urbiz

  why isnt my object being created? When I do it like so, I am told error C2065: 'AllReferrals' : undeclared identifier as well as error C2228: left of '.push_back' must have class/struct/union. If I put the list initialization before the class I get error C2065: 'AllReferrals' : undeclared identifier. Thanks! #include <iostream> #include <fstream> #include <regex> #include <string> #include <list> #include <map> using namespace std; using namespace tr1; class Referral { public: string url; map<string, int> keywords; static bool submit(string url, string keyword, int occurrences) { //if(lots of things i'll later add){ Referral(url, keyword, occurrences); return true; //} //else // return false; } private: list<string> urls; Referral(string url, string keyword, int occurrences) { url = url; keywords[keyword] = occurrences; AllReferrals.push_back(this); } }; static list<Referral> AllReferrals; int main() { Referral::submit("url", "keyword", 1); cout << AllReferrals.size(); cout << "\n why does that ^^ say 0 (help me make it say one)?"; cout << "\n and how can i AllReferrals.push_back(this) from my constructor?"; cout << " When I do it like so, I am told error C2065: 'AllReferrals' : undeclared identifier"; cout << " as well as error C2228: left of '.push_back' must have class/struct/union."; cout << " If I put the list initialization before the class I get error C2065: 'AllReferrals' : undeclared identifier."; cout << "\n\n\t Thanks!"; getchar(); }

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• Implementing default constructors

  - by James

  Implement the default constructor, the constructors with one and two int parameters. The one-parameter constructor should initialize the first member of the pair, the second member of the pair is to be 0. Overload binary operator + to add the pairs as follows: (a, b) + (c, d) = (a + c, b + d); Overload the - analogously. Overload the * on pairs ant int as follows: (a, b) * c = (a * c, b * c). Write a program to test all the member functions and overloaded operators in your class definition. You will also need to write accessor (get) functions for each member. The definition of the class Pairs: class Pairs { public: Pairs(); Pairs(int first, int second); Pairs(int first); // other members and friends friend istream& operator>> (istream&, Pair&); friend ostream& operator<< (ostream&, const Pair&); private: int f; int s; }; Self-Test Exercise #17: istream& operator (istream& ins, Pair& second) { char ch; ins ch; // discard init '(' ins second.f; ins ch; // discard comma ',' ins second.s; ins ch; // discard final '(' return ins; } ostream& operator<< (ostream& outs, const Pair& second) { outs << '('; outs << second.f; outs << ", " ;// I followed the Author's suggestion here. outs << second.s; outs << ")"; return outs; }

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• Copy constructor bug

  - by user168715

  I'm writing a simple nD-vector class, but am encountering a strange bug. I've stripped out the class to the bare minimum that still reproduces the bug: #include <iostream> using namespace std; template<unsigned int size> class nvector { public: nvector() {data_ = new double[size];} ~nvector() {delete[] data_;} template<unsigned int size2> nvector(const nvector<size2> &other) { data_ = new double[size]; int i=0; for(; i<size && i < size2; i++) data_[i] = other[i]; for(; i<size; i++) data_[i] = 0; } double &operator[](int i) {return data_[i];} const double&operator[](int i) const {return data_[i];} private: const nvector<size> &operator=(const nvector<size> &other); //Intentionally unimplemented for now double *data_; }; int main() { nvector<2> vector2d; vector2d[0] = 1; vector2d[1] = 2; nvector<3> vector3d(vector2d); for(int i=0; i<3; i++) cout << vector3d[i] << " "; cout << endl; //Prints 1 2 0 nvector<3> other3d(vector3d); for(int i=0; i<3; i++) cout << other3d[i] << " "; cout << endl; //Prints 1 2 0 } //Segfault??? On the surface this seems to work fine, and both tests print out the correct values. However, at the end of main the program crashes with a segfault, which I've traced to nvector's destructor. At first I thought the (incorrect) default assignment operator was somehow being called, which is why I added the (currently) unimplemented explicit assignment operator to rule this possibility out. So my copy constructor must be buggy, but I'm having one of those days where I'm staring at extremely simple code and just can't see it. Do you guys have any ideas?

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• Can't insert a number into a C++ custom streambuf/ostream

  - by 0xbe5077ed

  I have written a custom std::basic_streambuf and std::basic_ostream because I want an output stream that I can get a JNI string from in a manner similar to how you can call std::ostringstream::str(). These classes are quite simple. namespace myns { class jni_utf16_streambuf : public std::basic_streambuf<char16_t> { JNIEnv * d_env; std::vector<char16_t> d_buf; virtual int_type overflow(int_type); public: jni_utf16_streambuf(JNIEnv *); jstring jstr() const; }; typedef std::basic_ostream<char16_t, std::char_traits<char16_t>> utf16_ostream; class jni_utf16_ostream : public utf16_ostream { jni_utf16_streambuf d_buf; public: jni_utf16_ostream(JNIEnv *); jstring jstr() const; }; // ... } // namespace myns In addition, I have made four overloads of operator<<, all in the same namespace: namespace myns { // ... utf16_ostream& operator<<(utf16_ostream&, jstring) throw(std::bad_cast); utf16_ostream& operator<<(utf16_ostream&, const char *); utf16_ostream& operator<<(utf16_ostream&, const jni_utf16_string_region&); jni_utf16_ostream& operator<<(jni_utf16_ostream&, jstring); // ... } // namespace myns The implementation of jni_utf16_streambuf::overflow(int_type) is trivial. It just doubles the buffer width, puts the requested character, and sets the base, put, and end pointers correctly. It is tested and I am quite sure it works. The jni_utf16_ostream works fine inserting unicode characters. For example, this works fine and results in the stream containing "hello, world": myns::jni_utf16_ostream o(env); o << u"hello, wor" << u'l' << u'd'; My problem is as soon as I try to insert an integer value, the stream's bad bit gets set, for example: myns::jni_utf16_ostream o(env); if (o.badbit()) throw "bad bit before"; // does not throw int32_t x(5); o << x; if (o.badbit()) throw "bad bit after"; // throws :( I don't understand why this is happening! Is there some other method on std::basic_streambuf I need to be implementing????

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• SQL SERVER – Merge Operations – Insert, Update, Delete in Single Execution

  - by pinaldave

  This blog post is written in response to T-SQL Tuesday hosted by Jorge Segarra (aka SQLChicken). I have been very active using these Merge operations in my development. However, I have found out from my consultancy work and friends that these amazing operations are not utilized by them most of the time. Here is my attempt to bring the necessity of using the Merge Operation to surface one more time. MERGE is a new feature that provides an efficient way to do multiple DML operations. In earlier versions of SQL Server, we had to write separate statements to INSERT, UPDATE, or DELETE data based on certain conditions; however, at present, by using the MERGE statement, we can include the logic of such data changes in one statement that even checks when the data is matched and then just update it, and similarly, when the data is unmatched, it is inserted. One of the most important advantages of MERGE statement is that the entire data are read and processed only once. In earlier versions, three different statements had to be written to process three different activities (INSERT, UPDATE or DELETE); however, by using MERGE statement, all the update activities can be done in one pass of database table. I have written about these Merge Operations earlier in my blog post over here SQL SERVER – 2008 – Introduction to Merge Statement – One Statement for INSERT, UPDATE, DELETE. I was asked by one of the readers that how do we know that this operator was doing everything in single pass and was not calling this Merge Operator multiple times. Let us run the same example which I have used earlier; I am listing the same here again for convenience. --Let’s create Student Details and StudentTotalMarks and inserted some records. USE tempdb GO CREATE TABLE StudentDetails ( StudentID INTEGER PRIMARY KEY, StudentName VARCHAR(15) ) GO INSERT INTO StudentDetails VALUES(1,'SMITH') INSERT INTO StudentDetails VALUES(2,'ALLEN') INSERT INTO StudentDetails VALUES(3,'JONES') INSERT INTO StudentDetails VALUES(4,'MARTIN') INSERT INTO StudentDetails VALUES(5,'JAMES') GO CREATE TABLE StudentTotalMarks ( StudentID INTEGER REFERENCES StudentDetails, StudentMarks INTEGER ) GO INSERT INTO StudentTotalMarks VALUES(1,230) INSERT INTO StudentTotalMarks VALUES(2,255) INSERT INTO StudentTotalMarks VALUES(3,200) GO -- Select from Table SELECT * FROM StudentDetails GO SELECT * FROM StudentTotalMarks GO -- Merge Statement MERGE StudentTotalMarks AS stm USING (SELECT StudentID,StudentName FROM StudentDetails) AS sd ON stm.StudentID = sd.StudentID WHEN MATCHED AND stm.StudentMarks > 250 THEN DELETE WHEN MATCHED THEN UPDATE SET stm.StudentMarks = stm.StudentMarks + 25 WHEN NOT MATCHED THEN INSERT(StudentID,StudentMarks) VALUES(sd.StudentID,25); GO -- Select from Table SELECT * FROM StudentDetails GO SELECT * FROM StudentTotalMarks GO -- Clean up DROP TABLE StudentDetails GO DROP TABLE StudentTotalMarks GO The Merge Join performs very well and the following result is obtained. Let us check the execution plan for the merge operator. You can click on following image to enlarge it. Let us evaluate the execution plan for the Table Merge Operator only. We can clearly see that the Number of Executions property suggests value 1. Which is quite clear that in a single PASS, the Merge Operation completes the operations of Insert, Update and Delete. I strongly suggest you all to use this operation, if possible, in your development. I have seen this operation implemented in many data warehousing applications. Reference: Pinal Dave (http://blog.SQLAuthority.com) Filed under: Pinal Dave, SQL, SQL Authority, SQL Joins, SQL Query, SQL Scripts, SQL Server, SQL Tips and Tricks, T SQL, Technology Tagged: Merge

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• LINQ and ordering of the result set

  - by vik20000in

  After filtering and retrieving the records most of the time (if not always) we have to sort the record in certain order. The sort order is very important for displaying records or major calculations. In LINQ for sorting data the order keyword is used. With the help of the order keyword we can decide on the ordering of the result set that is retrieved after the query.  Below is an simple example of the order keyword in LINQ.     string[] words = { "cherry", "apple", "blueberry" };     var sortedWords =         from word in words         orderby word         select word; Here we are ordering the data retrieved based on the string ordering. If required the order can also be made on any of the property of the individual like the length of the string.     var sortedWords =         from word in words         orderby word.Length         select word; You can also make the order descending or ascending by adding the keyword after the parameter.     var sortedWords =         from word in words         orderby word descending         select word; But the best part of the order clause is that instead of just passing a field you can also pass the order clause an instance of any class that implements IComparer interface. The IComparer interface holds a method Compare that Has to be implemented. In that method we can write any logic whatsoever for the comparision. In the below example we are making a string comparison by ignoring the case. string[] words = { "aPPLE", "AbAcUs", "bRaNcH", "BlUeBeRrY", "cHeRry"}; var sortedWords = words.OrderBy(a => a, new CaseInsensitiveComparer());  public class CaseInsensitiveComparer : IComparer<string> {     public int Compare(string x, string y)     {         return string.Compare(x, y, StringComparison.OrdinalIgnoreCase);     } }  But while sorting the data many a times we want to provide more than one sort so that data is sorted based on more than one condition. This can be achieved by proving the next order followed by a comma.     var sortedWords =         from word in words         orderby word , word.length         select word; We can also use the reverse() method to reverse the full order of the result set.     var sortedWords =         from word in words         select word.Reverse();                                 Vikram

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• Asynchrony in C# 5 (Part I)

  - by javarg

  I’ve been playing around with the new Async CTP preview available for download from Microsoft. It’s amazing how language trends are influencing the evolution of Microsoft’s developing platform. Much effort is being done at language level today than previous versions of .NET. In these post series I’ll review some major features contained in this release: Asynchronous functions TPL Dataflow Task based asynchronous Pattern Part I: Asynchronous Functions This is a mean of expressing asynchronous operations. This kind of functions must return void or Task/Task<> (functions returning void let us implement Fire & Forget asynchronous operations). The two new keywords introduced are async and await. async: marks a function as asynchronous, indicating that some part of its execution may take place some time later (after the method call has returned). Thus, all async functions must include some kind of asynchronous operations. This keyword on its own does not make a function asynchronous thought, its nature depends on its implementation. await: allows us to define operations inside a function that will be awaited for continuation (more on this later). Async function sample: Async/Await Sample async void ShowDateTimeAsync() {     while (true)     {         var client = new ServiceReference1.Service1Client();         var dt = await client.GetDateTimeTaskAsync();         Console.WriteLine("Current DateTime is: {0}", dt);         await TaskEx.Delay(1000);     } } The previous sample is a typical usage scenario for these new features. Suppose we query some external Web Service to get data (in this case the current DateTime) and we do so at regular intervals in order to refresh user’s UI. Note the async and await functions working together. The ShowDateTimeAsync method indicate its asynchronous nature to the caller using the keyword async (that it may complete after returning control to its caller). The await keyword indicates the flow control of the method will continue executing asynchronously after client.GetDateTimeTaskAsync returns. The latter is the most important thing to understand about the behavior of this method and how this actually works. The flow control of the method will be reconstructed after any asynchronous operation completes (specified with the keyword await). This reconstruction of flow control is the real magic behind the scene and it is done by C#/VB compilers. Note how we didn’t use any of the regular existing async patterns and we’ve defined the method very much like a synchronous one. Now, compare the following code snippet  in contrast to the previuous async/await: Traditional UI Async void ComplicatedShowDateTime() {     var client = new ServiceReference1.Service1Client();     client.GetDateTimeCompleted += (s, e) =>     {         Console.WriteLine("Current DateTime is: {0}", e.Result);         client.GetDateTimeAsync();     };     client.GetDateTimeAsync(); } The previous implementation is somehow similar to the first shown, but more complicated. Note how the while loop is implemented as a chained callback to the same method (client.GetDateTimeAsync) inside the event handler (please, do not do this in your own application, this is just an example).  How it works? Using an state workflow (or jump table actually), the compiler expands our code and create the necessary steps to execute it, resuming pending operations after any asynchronous one. The intention of the new Async/Await pattern is to let us think and code as we normally do when designing and algorithm. It also allows us to preserve the logical flow control of the program (without using any tricky coding patterns to accomplish this). The compiler will then create the necessary workflow to execute operations as the happen in time.

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• concurrency::extent<N> from amp.h

  - by Daniel Moth

  Overview We saw in a previous post how index<N> represents a point in N-dimensional space and in this post we'll see how to define the N-dimensional space itself. With C++ AMP, an N-dimensional space can be specified with the template class extent<N> where you define the size of each dimension. From a look and feel perspective, you'd expect the programmatic interface of a point type and size type to be similar (even though the concepts are different). Indeed, exactly like index<N>, extent<N> is essentially a coordinate vector of N integers ordered from most- to least- significant, BUT each integer represents the size for that dimension (and hence cannot be negative). So, if you read the description of index, you won't be surprised with the below description of extent<N> There is the rank field returning the value of N you passed as the template parameter. You can construct one extent from another (via the copy constructor or the assignment operator), you can construct it by passing an integer array, or via convenience constructor overloads for 1- 2- and 3- dimension extents. Note that the parameterless constructor creates an extent of the specified rank with all bounds initialized to 0. You can access the components of the extent through the subscript operator (passing it an integer). You can perform some arithmetic operations between extent objects through operator overloading, i.e. ==, !=, +=, -=, +, -. There are operator overloads so that you can perform operations between an extent and an integer: -- (pre- and post- decrement), ++ (pre- and post- increment), %=, *=, /=, +=, –= and, finally, there are additional overloads for plus and minus (+,-) between extent<N> and index<N> objects, returning a new extent object as the result. In addition to the usual suspects, extent offers a contains function that tests if an index is within the bounds of the extent (assuming an origin of zero). It also has a size function that returns the total linear size of this extent<N> in units of elements. Example code extent<2> e(3, 4); _ASSERT(e.rank == 2); _ASSERT(e.size() == 3 * 4); e += 3; e[1] += 6; e = e + index<2>(3,-4); _ASSERT(e == extent<2>(9, 9)); _ASSERT( e.contains(index<2>(8, 8))); _ASSERT(!e.contains(index<2>(8, 9))); grid<N> Our upcoming pre-release bits also have a similar type to extent, grid<N>. The way you create a grid is by passing it an extent, e.g. extent<3> e(4,2,6); grid<3> g(e); I am not going to dive deeper into grid, suffice for now to think of grid<N> simply as an alias for the extent<N> object, that you create when you encounter a function that expects a grid object instead of an extent object. Usage The extent class on its own simply defines the size of the N-dimensional space. We'll see in future posts that when you create containers (arrays) and wrappers (array_views) for your data, it is an extent<N> object that you'll need to use to create those (and use an index<N> object to index into them). We'll also see that it is a grid<N> object that you pass to the new parallel_for_each function that I'll cover in the next post. Comments about this post by Daniel Moth welcome at the original blog.

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• Exporting makefile from Eclipse CDT

  - by Alex Farber

  I have C++ project in the Ubuntu OS, Eclipse CDT. My final goal is to build the project binaries for FreeBSD OS. The first test. I create simple C++ CDT project with main.cpp file: cout << "OK" << endl; and build it. Then I open Terminal window in Release directory: alex@alex-linux:~/workspace/HelloWorld/Release$ ls HelloWorld main.d main.o makefile objects.mk sources.mk subdir.mk alex@alex-linux:~/workspace/HelloWorld/Release$ rm HelloWorld main.d main.o alex@alex-linux:~/workspace/HelloWorld/Release$ ls makefile objects.mk sources.mk subdir.mk alex@alex-linux:~/workspace/HelloWorld/Release$ make Building file: ../main.cpp Invoking: GCC C++ Compiler g++ -O3 -Wall -c -fmessage-length=0 -MMD -MP -MF"main.d" -MT"main.d" -o"main.o" "../main.cpp" Finished building: ../main.cpp Building target: HelloWorld Invoking: GCC C++ Linker g++ -o"HelloWorld" ./main.o Finished building target: HelloWorld alex@alex-linux:~/workspace/HelloWorld/Release$ ./HelloWorld OK alex@alex-linux:~/workspace/HelloWorld/Release$ So far, so good. Now I copy the whole project tree to FreeBSD and trying to build it: $ cd /home/alex/project $ ls main.cpp release $ cd release $ ls makefile objects.mk sources.mk subdir.mk $ make "makefile", line 5: Need an operator "makefile", line 10: Need an operator "makefile", line 11: Need an operator "makefile", line 12: Need an operator CDT-generated makefile doesn't work. This is makefile beginning: $ Automatically-generated file. Do not edit! -include ../makefile.init RM := rm -rf $ All of the sources participating in the build are defined here -include sources.mk -include subdir.mk -include objects.mk ... Line 5 is -include ../makefile.init. Really, there is no such file. But it works by some way on Ubuntu computer. What is the trick, how can I build this? BTW, manually written makefile works: all: g++ -O0 -g3 -Wall -c -fmessage-length=0 -MMD -MP -MF"main.d" -MT"main.d" -o"main.o" "../main.cpp" g++ -o"HelloWorld" ./main.o Note: $ in makefile is actually #, I replaced it because # creates formatting problems inside of stackoverflow pre block.

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• NHibernate Query across multiple tables

  - by Dai Bok

  I am using NHibernate, and am trying to figure out how to write a query, that searchs all the names of my entities, and lists the results. As a simple example, I have the following objects; public class Cat { public string name {get; set;} } public class Dog { public string name {get; set;} } public class Owner { public string firstname {get; set;} public string lastname {get; set;} } Eventaully I want to create a query , say for example, which and returns all the pet owners with an name containing "ted", OR pets with a name containing "ted". Here is an example of the SQL I want to execute: SELECT TOP 10 d.*, c.*, o.* FROM owners AS o INNER JOIN dogs AS d ON o.id = d.ownerId INNER JOIN cats AS c ON o.id = c.ownerId WHERE o.lastname like '%ted%' OR o.firstname like '%ted%' OR c.name like '%ted%' OR d.name like '%ted%' When I do it using Criteria like this: var criteria = session.CreateCriteria<Owner>() .Add( Restrictions.Disjunction() .Add(Restrictions.Like("FirstName", keyword, MatchMode.Anywhere)) .Add(Restrictions.Like("LastName", keyword, MatchMode.Anywhere)) ) .CreateCriteria("Dog").Add(Restrictions.Like("Name", keyword, MatchMode.Anywhere)) .CreateCriteria("Cat").Add(Restrictions.Like("Name", keyword, MatchMode.Anywhere)); return criteria.List<Owner>(); The following query is generated: SELECT TOP 10 d.*, c.*, o.* FROM owners AS o INNER JOIN dogs AS d ON o.id = d.ownerId INNER JOIN cats AS c ON o.id = c.ownerId WHERE o.lastname like '%ted%' OR o.firstname like '%ted%' AND d.name like '%ted%' AND c.name like '%ted%' How can I adjust my query so that the .CreateCriteria("Dog") and .CreateCriteria("Cat") generate an OR instead of the AND? thanks for your help.

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• Help with boost::lambda expression

  - by Venkat Shivanandan

  I tried to write a function that calculates a hamming distance between two codewords using the boost lambda library. I have the following code: #include <iostream> #include <numeric> #include <boost/function.hpp> #include <boost/lambda/lambda.hpp> #include <boost/lambda/if.hpp> #include <boost/bind.hpp> #include <boost/array.hpp> template<typename Container> int hammingDistance(Container & a, Container & b) { return std::inner_product( a.begin(), a.end(), b.begin(), (_1 + _2), boost::lambda::if_then_else_return(_1 != _2, 1, 0) ); } int main() { boost::array<int, 3> a = {1, 0, 1}, b = {0, 1, 1}; std::cout << hammingDistance(a, b) << std::endl; } And the error I am getting is: HammingDistance.cpp: In function ‘int hammingDistance(Container&, Container&)’: HammingDistance.cpp:15: error: no match for ‘operator+’ in ‘<unnamed>::_1 + <unnamed>::_2’ HammingDistance.cpp:17: error: no match for ‘operator!=’ in ‘<unnamed>::_1 != <unnamed>::_2’ /usr/include/c++/4.3/boost/function/function_base.hpp:757: note: candidates are: bool boost::operator!=(boost::detail::function::useless_clear_type*, const boost::function_base&) /usr/include/c++/4.3/boost/function/function_base.hpp:745: note: bool boost::operator!=(const boost::function_base&, boost::detail::function::useless_clear_type*) This is the first time I am playing with boost lambda. Please tell me where I am going wrong. Thanks.

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• "import numpy" tries to load my own package

  - by Sebastian

  I have a python (2.7) project containing my own packages util and operator (and so forth). I read about relative imports, but perhaps I didn't understand. I have the following directory structure: top-dir/ util/__init__.py (empty) util/ua.py util/ub.py operator/__init__.py ... test/test1.py The test1.py file contains #!/usr/bin/env python2 from __future__ import absolute_import # removing this line dosn't change anything. It's default functionality in python2.7 I guess import numpy as np It's fine when I execute test1.py inside the test/ folder. But when I move to the top-dir/ the import numpy wants to include my own util package: Traceback (most recent call last): File "tests/laplace_2d_square.py", line 4, in <module> import numpy as np File "/usr/lib/python2.7/site-packages/numpy/__init__.py", line 137, in <module> import add_newdocs File "/usr/lib/python2.7/site-packages/numpy/add_newdocs.py", line 9, in <module> from numpy.lib import add_newdoc File "/usr/lib/python2.7/site-packages/numpy/lib/__init__.py", line 4, in <module> from type_check import * File "/usr/lib/python2.7/site-packages/numpy/lib/type_check.py", line 8, in <module> import numpy.core.numeric as _nx File "/usr/lib/python2.7/site-packages/numpy/core/__init__.py", line 45, in <module> from numpy.testing import Tester File "/usr/lib/python2.7/site-packages/numpy/testing/__init__.py", line 8, in <module> from unittest import TestCase File "/usr/lib/python2.7/unittest/__init__.py", line 58, in <module> from .result import TestResult File "/usr/lib/python2.7/unittest/result.py", line 9, in <module> from . import util File "/usr/lib/python2.7/unittest/util.py", line 2, in <module> from collections import namedtuple, OrderedDict File "/usr/lib/python2.7/collections.py", line 9, in <module> from operator import itemgetter as _itemgetter, eq as _eq ImportError: cannot import name itemgetter The troublesome line is either from . import util or perhaps from operator import itemgetter as _itemgetter, eq as _eq What can I do?

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